I'm having a problem with smaller features of the first layer adhering properly - the skirt and outline of the object print fine, but the outline for a small hole in the center (2mm diameter) lifts right off and gets carried by the head to glob up on (and sometimes lift off) the next extrusion, which is usually the next layer of outline for the larger object.
I've tried releveling the bed, using the "official" plastic-coated paper Ultimaker leveling card, tightening until there's just friction on the paper, changing the first layer speed from its default of 15mm/s to 10 and 20. Pretty sure I left the default PLA temperatures in the printer of bed 60, head 210.
Also scraped the old glue off the bed and reapplied new glue stick, to no avail.
I have a UM2Extended+, using Matterhackers' black PLA, and otherwise Cura's defaults.
The model I'm using is here, and I'll attach a link to the Openscad source once I upload it to GitHub.
Edit: Here's that link: House Numbers.scad